TryHackMe c4ptur3-th3-fl4g Writeup: Encoding, Spectrograms, and Steganography
A TryHackMe c4ptur3-th3-fl4g walkthrough covering binary, Base32, Base64, ROT, Morse, spectrograms, steghide, and strings-based file inspection.
This writeup is adapted from my original TryHackMe notes for c4ptur3-th3-fl4g. I kept the room flow close to the source Markdown and cleaned up GitBook formatting so it reads properly on the website.
Answer the questions below
Task 1 Translation & Shifting
Translate, shift and decode the following;
Answers are all case sensitive.
https://gchq.github.io/CyberChef
c4n y0u c4p7u23 7h3 f149?
Answer: Can you capture the flag?
01101100 01100101 01110100 01110011 00100000 01110100 01110010 01111001 00100000 01110011 01101111 01101101 01100101 00100000 01100010 01101001 01101110 01100001 01110010 01111001 00100000 01101111 01110101 01110100 00100001
Binary -> Answer
Answer: lets try some binary out!
MJQXGZJTGIQGS4ZAON2XAZLSEBRW63LNN5XCA2LOEBBVIRRHOM======
Base32 -> Answer
echo "MJQXGZJTGIQGS4ZAON2XAZLSEBRW63LNN5XCA2LOEBBVIRRHOM======" | base32 -d
Answer: base32 is super common in CTF's
RWFjaCBCYXNlNjQgZGlnaXQgcmVwcmVzZW50cyBleGFjdGx5IDYgYml0cyBvZiBkYXRhLg==
Base64 -> Answer
echo "RWFjaCBCYXNlNjQgZGlnaXQgcmVwcmVzZW50cyBleGFjdGx5IDYgYml0cyBvZiBkYXRhLg==" | base64 -d
Answer: Each Base64 digit represents exactly 6 bits of data.
68 65 78 61 64 65 63 69 6d 61 6c 20 6f 72 20 62 61 73 65 31 36 3f
Hex -> Answer
Answer: hexadecimal or base16?
Ebgngr zr 13 cynprf!
ROT13 -> Answer
Answer: Rotate me 13 places!
*@F DA:? >6 C:89E C@F?5 323J C:89E C@F?5 Wcf E:>6DX
ROT47 -> Answer
Answer: You spin me right round baby right round (47 times)
- . .-.. . -.-. --- -- -- ..- -. .. -.-. .- - .. --- -. . -. -.-. --- -.. .. -. --.
Morse Code -> Answer
Answer: TELECOMMUNICATIODNCODING
85 110 112 97 99 107 32 116 104 105 115 32 66 67 68
Decimal -> Answer
Answer: Unpack this BCD
LS0tLS0gLi0tLS0gLi0tLS0gLS0tLS0gLS0tLS0gLi0tLS0gLi0tLS0gLS0tLS0KLS0tLS0gLi0tLS0gLi0t...Li0tLS0=
Base64 -> Morse Code -> Binary -> ROT47 -> Decimal -> Answer
Answer: Let's make this a bit trickier...
Task 2 Spectrograms
A spectrogram is a visual representation of the spectrum of frequencies of a signal as it varies with time. When applied to an audio signal, spectrograms are sometimes called sonographs, voiceprints, or voicegrams. When the data is represented in a 3D plot they may be called waterfalls.
Download the file
To use a spectrogram layer in Sonic Visualiser.
Answer: Super Secret Message
Task 3 Steganography
Steganography is the practice of concealing a file, message, image, or video within another file, message, image, or video.
Decode the image to reveal the answer.
file stegosteg_1559008553457.jpg
steghide extract -sf stegosteg_1559008553457.jpg
cat steganopayload2248.txt
Answer: SpaghettiSteg
Task 4 Security through obscurity
Security through obscurity is the reliance in security engineering on the secrecy of the design or implementation as the main method of providing security for a system or component of a system.
strings meme_1559010886025.jpg
Download and get 'inside' the file. What is the first filename & extension?
Answer: hackerchat.png
Get inside the archive and inspect the file carefully. Find the hidden text.
Answer: AHH_YOU_FOUND_ME!